House sellers are rushing to put their properties on the market before June 1 to avoid paying for a home information pack, according to a report today.

There could be a shortage of homes for sale immediately after this date, according to the Royal Institution of Chartered Surveyors, which published the report. Conditions were expected to "tighten" as sellers withdrew from the market.

Its comments come before two parliamentary debates at which some MPs and peers are likely to call for home information packs (Hips) to be delayed or scrapped altogether.

Under the scheme, described as the biggest change for years in the way people buy and sell homes, anyone selling a property after June 1 will first have to assemble a pack containing detailed information about their house or flat - at a cost of several hundred pounds. The packs are aimed at making the home-buying process more efficient, slashing the number of collapsed transactions and encouraging homeowners to reduce energy consumption. Critics say they will bring little benefit to the consumer and will have an adverse effect on the housing market.

In its latest monthly survey, based on comments from its surveyor and estate agent members, Rics said house prices rose for the 18th consecutive month in April, despite the imminent introduction of Hips pushing more property on to the market.

New instructions rose for the second month in April after the longest decline in seven years. "The pick-up appears to be closely related to the planned introduction of Hips rather than any decline in the state of household finances. Surveyors report that increasing numbers of sellers are listing their properties early in order to avoid the up-front cost of assembling the pack," a spokesman said. As a result, the stock of unsold properties on surveyors' books increased for the first time since November.

Official figures from the Department for Communities and Local Government, also published yesterday, showed that the cost of an average home rose by £2,000 in March to reach £206,890. This figure is £20,000 higher than a year ago. The average price of a London home has jumped by £42,000 in a year.

Yesterday, MPs and peers attended an "emergency briefing" on Hips organised by Rics, which is trying to persuade politicians to support its call for the packs to be delayed. There will be a Commons debate tomorrow, which follows the tabling of a motion by the Conservative leader, David Cameron, calling for the home information pack regulations to be annulled. A second debate in the House of Lords is to take place on May 22.

Earlier this month, an all-party House of Lords committee questioned whether the packs would achieve their aims, and said the government needed to do much more if it wanted to win over those who had written them off as a waste of time.

Rics said the Hip was a "poor and expensive" product, and that the June 1 start date was "completely unworkable". The spokesman said between 4,000 and 5,000 people would be needed to carry out home inspections and energy assessments, but added that the government's own figures showed only 1,902 people had so far passed the relevant exams.